1. Field of the Invention
The present invention relates to an x-ray radiator of the rotary-bulb type having a vacuum enclosure which rotates within the radiator housing during the operation of the x-ray radiator, the radiator housing, being filled with a liquid cooling medium.
2. Description of the Prior Art
In x-ray radiators such as this, oil pumps and external coolers are sometimes forgone for reasons of cost. This means that in x-ray radiators of this type the high heat energy which is created in the x-ray conversion must be stored in the anode, and the stored heat is then conveyed to the liquid cooling medium, from which it can be released into the environment exclusively by means of convection. In turn, this means that x-ray radiators of this type can only by designed for an average power of a few 100 Watts. Besides this power limitation, a further disadvantage is that the overall cooling medium volume (generally insulating oil) of the x-ray radiator is not heated uniformly by the heat arising locally in the vicinity of the anode, and so heat is not uniformly converted through the surface of the x-ray radiator, which means that the x-ray radiator cannot be operated at a continuous power which would be optimal for the volume. Finally, in x-ray radiators of this type the danger exists that parts of the housing in the region of the anode may exceed the allowable temperature limits.
If it is desired to increase the power of x-ray radiators without external coolers, a forced-air cooling can be introduced, however, this does not solve the problem of uneven heat discharge by the tube. Besides a limited possibility to increase power, the cost reduction resulting from the avoidance of the external cooler, which is desirable, is not achieved with such a forced-air cooling, or only to a certain extent.